


In a Blink

by orphan_account



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Battle of Garreg Mach, Developing Relationship, Fire Emblem: Three Houses Blue Lions Route Spoilers, M/M, Post-Time Skip, Pre-Time Skip
Language: English
Status: In-Progress
Published: 2019-09-02
Updated: 2019-09-02
Packaged: 2020-10-05 20:48:45
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 4,319
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20495111
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: Though the five years after the Battle of Garreg Mach passed in a handful of minutes for Byleth, the same cannot be said for the rest of the Blue Lions.The complications from all the time he lost have left seemingly Byleth out of place as the war continues around them all.





	1. Chapter 1

**Author's Note:**

> I'll be honest, I've got several documents open with Three Houses prompts/fledgling fics right now. I've sort of been alternating between them as I've been going through the other routes in the game, so I figured I might as well post the first part of one of them! I saw this as a kind of prequel to 'Share Your Secrets', but you absolutely don't need to have read it for this to make sense.
> 
> This started because I was explaining the Battle of Garreh Mach and the differences between paths to a friend, and we started calling the battle 'that one time Byleth got yeeted off an mountain'.
> 
> And I guess I like writing silly emotional stuff.

When the first clash with Empire forces was but hours away, Rhea had called Byleth for a private meeting. She informed him - not asked or suggested, _told_ \- that he was to succeed her should anything happen to her. Her words alone made it seem like a vague possibility, but her tone and manner made it feel inevitable. He was to take her place as the protector of the people, as if she was going to be unable to continue to do so herself. As if she were tying up loose ends, as if she thought she was going to die on the battle field. 

On the ridge overlooking the battle hours lshe reminded him again. He was to take her place and shoulder her burdens. All the while, her eyes were so terribly sad.

Then she dismissed him, and he ran.  
  
Byleth immediately headed towards the last place he had seen his students, his Blue Lions. They were scattered about as they fought to keep the Imperial troops who managed to get past the Knights at bay and evacuate as many citizens as they could. He assisted until a lull presented itself.  
  
"Blue Lions! Everyone! Gather up!"  
  
The word travelled fast. Dimitri was closest and the first to join him. He looked tired - though Byleth was willing to admit they must all look tired. A battle like this hardly cropped up often. Dedue was at his prince's shoulder, somehow seeming calm despite it all. From all he's seen of Dedue, Byleth wasn't surprised to see him taking the madness in stride.  
  
Mercedes and Annette were the next to arrive, hand in hand. The day that the two of them separated for long was going to mark the end of the world as they knew it. Ashe was on their tail, and looking out past those gathered Byleth could see Ingrid and Sylvain having to practically drag Felix away from the chaos. As soon as the last three were in earshot, Byleth spoke.  
  
"Garreg Mach is lost. We're outnumbered and I refuse to see any of you fall here. Living to fight another day is our only option." Byleth paused to take a breath and quickly glance around the area. Good. They had a few more minutes. "You all are to watch each others backs and get back to Faerghus. Go home. We can all regroup there, far away from this. Report to your families, alert as many of the houses as you can - we'll need resources if we wish to stand a chance against the Empire."  
  
A loud bang, followed by monstrous roar drew all their attention back to the ongoing battle around them. Byleth's eyes widened in shock - the ridge, the noise was coming from the ridge.  
  
Rhea.  
  
"Go! You all _must_ survive this. I have to find Rhea, but I'll catch up to you. We'll meet in Faerghus. I'll find you."  
  
Dimitri look thunderous, and he seemed ready to ignore Byleth's orders. He stood tensed, as if he were ready to bolt. Then the moment passed and he let out a heavy sigh. He said nothing as he turned to Dedue and started away from their tiny group. Away from the monastery.  
  
The lot of them looked devestated. Mercedes looked near tears, while Annette and Ashe simply looked empty. But Mercedes was strong - much stronger than anyone gave her credit for - and began to herd Annette and Ashe after Dimitri. Ingrid had already donned a determined face and was set to lead Sylvain and Felix off with the rest. They were a good group. As long as they stuck together and acted as a solid unit, Byleth couldn't imagine anything stopping them.  
  
As the last of them shifted to follow Dimitri, Byleth darted forward to catch Felix by the arm. He pulled him around until they were facing each other.  
  
"Felix, listen to me. I need to you stick with Ingrid and Sylvain, no matter what. Watch their backs and for heaven's sake let them watch yours. Don't run off by yourself. Don't start fights you can't win. Try to be civil with Dimitri. Play everything safe, stay in one piece, and stay alive. Do you understand me?"  
  
Felix was blankly staring at him, silent, the rage from earlier still firmly in place yet... distant. Byleth grasped his shoulders and tried again.  
  
"You are strong, but you are not invincible. You have to rely on the others sometimes. Do you understand me?"  
  
Felix huffed, came fully back to himself, and pinned Byleth with an accusing look. "This sounds like you're trying to say goodbye. Like you won't be coming back."  
  
Byleth's stoic mask crumpled at that. "Of course I'll be back. I'm just going to find Rhea and then head to meet you. All of you."  
  
When Felix's look didn't diminish in the slightest, he tried again. "I promise that I'll be back."  
  
The anger on his face shifted, and Felix's eyes dropped to look into the space over Byleth's shoulder. Something he couldn't quite identified flashed there, and before he had much of a chance to say or do anything, Felix was meeting his eyes again. He surged forward, reached up to bury his hands in the light, oddly green hair at the base of his skull and pulled Byleth to meet him. It was a rough and violent kind of kiss that was over within seconds. Before he's had much of a chance to process what was going on, Felix was pulling back and refusing to meet his eyes.  
  
"You had better be back."  
  
With that, he turned on his heel and jogged to catch back up to Ingrid and Sylvain. He never looked back. Byleth stood there, still in a sort of shock, for longer than he would have liked to admit.  
  
Sure, he wasn't about to argue or complain about that... interesting develoment. But dear heavens did Felix have horrible timing. Byleth shook himself (as if that would help clear his head) and returned his attention to the ridge. Starting towards it, he had to wonder if just _perhaps_, Felix's timing was as good as it was going to get. All things considered.  
  
Events seemed to speed up tenfold when he cleared the hill. The source of the aforementioned roaring was stunning - a brilliant white creature Byleth could only call a dragon was fighting against both Demonic Beasts and plenty Imperial soldiers. Rhea was no where to be seen.  
  
The Beasts swarmed the dragon, and at first it seemed like it would be able to deal with them. As they clambered over the creature, Byleth lept into action. He drew his sword, already glowing with that bright energy, and dispatched one of the beasts. That was enough for the dragon to throw the rest off its back. One crashed into the weakened wall, broke through, and tumbled into the empty space. If the dragon hadn't killed it already, Byleth was certain that the fall down the mountain would do it in.  
  
Nothing could survive that fall.  
  
Byleth was still looking toward the drop when the dragon landed in front of him. It opened its mouth and Byleth wondered what kind of destruction would follow. Instead, it spoke.  
  
"Why did you come?"  
  
That voice was familiar but that just didn't make sense. It's voice - no _her_ voice - was so familiar that Byleth almost couldn't believe it. Then he registered the words. Why had he come? But no, that didn't make sense either. She couldn't have meant him. And if she wasn't talking to him, then who was she -?  
  
When the realization hit, he whipped around to see the man standing on the ridge. The same inhuman looking beast that had saved Kronya after she'd murdered Jeralt, murdered his father right in front of him. Byleth brought the Sword of the Creator back to the ready position in a flash.  
  
The monster of a man, Thales, gathered a dark ball of energy between his hands and shot it at him with that cruel smile on his face. Byleth remembered his first battle against a mage with the Sword and stood to intercept the spell.  
  
Only, this time, he was unable to split and disperse the magic. No, this time it simply pushed him back until he lost his footing and fell back into the same void that the Beast had moments before.  
  
He didn't feel any impact. He only heard the dragon - Rhea, it _had_ to be - screaming as everything went black around him.  



	2. Chapter 2

**Notes for the Chapter:**

> This is a very Byleth focussed chapter. I wanted to take the time to explore a few things before adding more to it.
> 
> Apologies for any typos I may have missed in a quick edit!

When he opened his eyes again and was able to see more than the darkness, Byleth was surprised to find himself on the river bank. Gone was the warm blackness, replaced now by a permeating cold. How had he ended up in the river?  
  
Then it came back to him. Sothis. His friend, his closest friend, had spoken to him again. She had to have been the one behind his survival. There was simply no other way for him to still be alive. He'd been unable to see her, but she had lectured him all the same. She'd told him to hurry up and to wake up. So demanding, so pushy...  
  
It was familiar and comforting.  
  
"Um, hello?"  
  
Byleth stood quickly and came face to face with a villager.  
  
"Oh, good. I was worried when I saw you floating down the river! How did you end up in there anyway?"  
  
Byleth didn't say anything, and the man continued.  
  
"The river starts up near Garreg Mach. Nobody's up there anymore, no one except thieves, bandits, and a monster. Doesn't explain how you got in the river..."  
  
"Wait, stop. No one is up there anymore?"  
  
"Uh, no? The Church of Seiros isn't up there anymore. Not since the battle five years back. A real shame, considering the Millenium Festival's here."  
  
"Five years ago?"  
  
"Are you okay, buddy? Did you hit your head when you fell?"  
  
Byleth shook his head mutely, carefully keeping his face completely blank. Then he nodded and turned away from the man.  
  
"Hey! Where are you going? Don't go up there, man, I won't tell anyone you're a coward!"  
  
Completely ignoring the man, Byleth started the long climb back up the mountain to Garreg Mach. All those stairs were sure to give him plenty of time to think.  
  
~  
  
The closer he came to the monastery, the more bodies Byleth saw. Some of the corpses were old - perhaps dating back to the Battle of Garreg Mach itself (Could what the villager said earlier really be true? Had he really missed five whole years?) while others were astoundingly fresh. Most wore Imperial Army uniforms, but there were a few in the rag-tag assortment of armor that Byleth had long associated with bandits or thieves. Soldiers and opportunists alike had met their end thanks to whatever was guarding the monastery.  
  
Identities and motivations of the those killed aside, one thing became clear: whoever was living in the monastery had been very, very busy.  
  
~  
  
He had taken his sweet time wandering towards the Goddess Tower. If anyone was in the monastery still, Byleth was willing to bet that they would stay close to the cathedral itself. Perched on the mountain as it was, it would not have been too hard to defend. Not to mention the simple significance of the building.  
  
Byleth spent the entire walk noting all the damage. Some was obviously due to the fighting - smashed windows, broken walls, and general destruction. But the overgrowth of all the plants, the dust and dirt that permeated the site, that was certainly due to the monastery's abandonment. It was impossible to continue doubting the idea that he had lost time. All of this couldn't have happened in the few days that he felt had passed.   
  
He only peeked into the cathedral before deciding to take the outter path. The collapsed dome and the many shattered stained-glass windows were painful to look at. It was all more and more proof that he'd lost more than a single battle.   
  
Sure enough, someone was in the Goddess Tower. Byleth was sure they knew he was there. How could they not, when his footsteps echoed in the total silence? He was then surprised when the person - a giant of a man, draped in heavy furs and seemingly propped up with his spear - didn't acknowledge him immediately.  
  
His eyes took several moments to adjust to the gloom. When they did, he was able to pick out more details of the person seated on the floor. A messy mop of blond hair, the blood splattered all about him, a dark patch over his eye...  
  
Byleth had a guess as to who this stranger was. Acting on that hunch, he took several steps until he stood before the man and then offered him a hand, as if to help him off the floor.  
  
It was then that the man spoke.  
  
"I should have known... That one day, you would be haunting me as well."  
  
There it was. That broken boy who had snapped and fragmented on that day in the Holy Tomb.   
  
"I'm no ghost, Dimitri. I'm here. I came back for you."  
  
~  
  
If dealing with a scattered group of thieves - and yes, Byleth felt Dimitri was being just a touch dramatic, what with the constant comments about the 'rats'. Had he always been like this? - was what it was going to take to get Dimitri to stop thinking he was a particularily stubborn halluncination, he was more than willing to fight. And if fighting would make the entirety of the day feel real (instead of like a twisted dream)... Well, he couldn't say that he _wanted_ this mess of a world to be real, but it would be preferable to going about his days as if waiting to wake up.  
  
All the same, it was obvious that Dimitri didn't need the help. While years may have passed in a sort of a blink of an eye for Byleth, it was apparent that those years had passed slowly and painfully for his old student. And if that time had done this to the leader of their house... He was afraid to see what the time had done to the others.  
  
~  
  
Byleth was glad to see that his fears were mostly unfounded. Ashe and Gilbert had appeared first. The boy had grown up, yes, but he was still the sweet hearted boy Byleth had spent hours training with. And his archery had truly improved. Byleth hoped the improvement was due to practice rather than necessity.  
  
Annette and Mercedes arrived together. A spitfire of a mage and a mature cleric, ever joined at the hip. He was so proud to see them throw themselves into the fight, dedicated to protecting their friends. They were nothing if not reliable.  
  
The last three entered the battle with a touch more fanfare. Ingrid was the first one he saw, her white pegasus surely drawing everyone's attention. She struck quite the picture with a lance in hand and determination in her eyes. Sylvain's arrival was louder, simply due to the fact he was quick to yell greetings to the lot of them. Nothing could dull his spirit.  
  
Byleth wasn't able to find Felix until the boy - and could he really call him that? Call any of them that? They'd all grown up so much in those years he had lost - popped up behind the thieves' leader. None of them stood a chance. Felix, like the rest of his house, had obviously spent his time refining his skills. If he had been a menace on the battlefield when he was a student at the officer's academy, now he was a holy terror. His opponents felt before him before they had a chance to retaliate. Byleth couldn't help the swell of pride he felt at that. He stood back and watched Felix actually work alongside both Sylvain and Ingrid while they swept up the last of the theives. Felix had listened to him. He was still in the thick of it, but he was protecting his friends and letting them watch his back.  
  
Goddess, they'd all grown up so much.  
  
Admiring them all only made his heart hurt when he noticed that they were one member short. No wonder Dimitri was unhinged. He'd lost Dedue.  
  
The lot of them gathered around him once all the theives had been delt with. Most of them were elated and grinning ear-to-ear just to be almost all together again. The mood was slightly soured by Dimitri's doom and gloom demeanor, but Byleth was determined not to let the prince's ill temper ruin their little reunion.  
  
And he was especially determined not to look too much into how Felix had set his jaw and was pointedly refusing to meet his eyes. Byleth couldn't blame him for it, not really. Not after he'd abandoned them, unintentional as it may have been. He'd made a promise and then broken it before it was an hour old.  
  
~  
  
After the long events of the day, Byleth was certain that he should be exhausted. The theives and Dimitri's bloodlust had done a fair job at tiring him physically, and the sheer insanity of his situation coupled with the reunion with his students had him mentally drained.  
  
Yet here he was, wide awake and almost jittery in the middle of the night.  
  
Byleth heaved a sigh before he got off of his bed. A walk about the monastery was as likely as not to calm his nerves. And if it failed to do that, it may just tire him enough to finally sleep. He was quick to pull his clothes back on - just his black undershirt, pants, boots, and trusted dagger before he was out the door. Trotting down the steps and making a sharp right, he fumbled the last buttons and the clasp holding the collar flush at his throat. The Ethereal Moon coupled with the night air left the monastery feeling frigid and uninviting, but Byleth refused to go back and grab his cloak. He let his feet carry him where they may, past all the old dorm rooms and to the greenhouse.  
  
The greenhouse most clearly showed his lost years. It was painfully overgrown, obvious even in the moonlight. The flowers and vegetables Ashe and Dedue had helped him plant what felt like a week ago had in turn taken over the garden. Plants spilled from the scattered broken panes, turning the structure into a wild jungle. Weeds had taken up residence where they would have once been unable to take root. Byleth was in no way looking forward to straightening _that_ disaster.  
  
He slowly turned away from the greenhouse with shake of his head. That was a mess for future-Byleth, for the daylight. From there he let himself wander aimlessly. The pond was still teaming with fish. The main hall was full of cobwebs. The stables were a great deal messier than Cyril could have ever imagined. Books were on the floor in the knight's hall, and broken weapons and gear had been discarded in the corners.  
  
The monastery felt foreign to him is all its disrepair.  
  
Byleth's feet eventually led him to the cemetary. In truth, he had been trying to ignore the place. Going there would have forced him to accept all of this. The Millenium Festival had been on the horizon, according to the villager at the base of the mountain. He'd lost his father, seen Jeralt murdered by that Kronya creature, two days after the Ball. The 26th day of the Ethereal Moon. While he wasn't entirely sure of the current date, it was close enough to what had to be the anniversary to make Byleth's chest feel incredibly tight.  
  
He stood at the top of the staircase for a while, staring at the base of the steps as if it was some great obstacle or fearsome beast. It took a number of deep breaths and a fair bit of mental cajoling before he was able to take the stairs.  
  
Standing in front of that grave was harder than he imagined.  
  
As it had been the first time he saw it, the name of his mother had worn away and lost. With only the years '_1139 - 1159_' to sum up her entire existence, Byleth only felt curiosity about her. He couldn't miss what he had never known.  
  
_Jeralt Eisner_  
_ ???? - 1180_  
  
He had only had three months and a handful of days to process his father's death. Edelgard had led the attack on Garreg Mach, and Byleth had fallen. His fairly simple existence had ended then, too. He couldn't explain what had happened to him, aside from the feeling that Sothis was behind it. Five years gone in a blink of an eye.  
  
The gravestone looked different than he remembered. His father's name was worn from years of wind and rain, from the seasons turning and from a lack of maintenance. It was still so easy to read, but so many of the sharp angles were starting to go smooth.  
  
Byleth found himself unable to continue looking at the stone and equally unable to leave. He settled for a happy medium instead, walking around the stone to lean on the short wall protecting the cemetary from the steep drop into nothingness. In the distance and off to his left was the bridge and the cathedral, looking so sad and lonely in the moonlight.  
  
He scrubbed his hands over his face in an attempt to stave off all the emotions threatening to overtake him. How cruel it all was. Jeralt had so often poked fun at his stoicism while he had been growing up. He hadn't cried any of the times he'd fallen or when hurt himself in training. He hadn't reacted much at all to the nasty ambush when he was a teenager that had nearly taken his left knee out. No, he'd just asked Jeralt to help him find armor to protect him from it ever happening again once he'd healed. He'd been blank for so damn long. Yet now that Jeralt was gone, here he was completely unable to turn it all back _off_.  
  
His father had died and now all he felt was that crushing sadness. Yes, some good had come before all that sadness - between Sothis's company and his students, he had smiled more in those short months than he had in all the years before. He almost wished to go back to the 'before' where he felt little, displayed less, and everything was safe.  
  
But no. Byleth was stuck in the 'here' and the 'now'. His life was emotions he didn't know how to deal with, a gaping hole where his unbeating heart was, and everything he'd known lost to time.  
  
Byleth felt his vision go blurry and reached uo to rub at his eyes again. When his fingers came away wet, he couldn't help but laugh.  
  
"Bet you never thought I'd turn into a crybaby, huh?"   
  
Byleth tugged at his sleeve to dab at his eyes, the cold feeling sharper than it had when he'd left his room. The shaking breaths he took were icy. But not icy enough to scare him back indoors.  
  
"It just took, ah..." He paused, brows furrowed before taking a few steps backwards to look at his parents' headstone again. He didn't let himself read the phrase carved there, only the years, before going back to the wall. "If she died in 1159 like he said, I was... Twenty-one or so when we came here? It took twenty years for me to turn into this mess."  
  
He sniffed weakly. Try as he might, he wasn't quite able to just will it all away. The tears kept coming, just like they during those weeks after Jeralt's death. It would just have to be enough that his breathing was evening out.  
  
"Oh Goddess. How old would I even be now? Twenty-six years since I was born, but a fifth of that asleep?" He could hardly help the joyless, sharp laugh that came then, "I'm starting to see the appeal in not knowing or caring about my age. Just like you."  
  
Byleth wasn't sure how long he stayed out there after that, occaisonally talking to the stone and the dark, empty sky. Once his fingers and toes were completely numb and his nose was stinging and most certainly red, he opted to climb the steps and take a short-cut through the main hall back to his room. The sky was just starting to lighten.  
  
Either he'd spent far longer laying in bed awake than he'd thought, or he'd effectively gotten lost in his own head in the cemetary. It hardly mattered which, in the end. The result was that he only had a few hours to sleep and hope he didn't look at wrecked as he felt. What a way to turn up to the inevitable strategy meeting.   
  
Once he'd skirted the old classrooms and made it back to the dormitories, he was quick to hop up the steps to his door. He hadn't locked the door when he left and was thoughtlessly quick to step inside.  
  
The door had only just barely closed when Byleth registered he wasn't alone. He didn't fight back when the person pushed him back against the door hard enough to make him crack his head hard enough to see stars. He blinked rapidly in hopes to both clear his vision and make his eyes fully adjust faster, paying little mind to how the stranger was pressing their forearm up against his collarbones to keep his shoulders pressed against the door.  
  
It only took a moment or two for him to recognize his violent visitor. He had it just a second before he spoke.  
  
"What the _hell_, Professor?"  
  
Byleth sighed and let his head fall back against the door with another _thunk_ before he spoke.   
  
"Hello to you, too, Felix."

**Author's Note:**

> And that's the first part! I'll do my best to get everything written and the rest up!
> 
> Listening to the newish Bastille album (Doom Days) has honestly been my constant soundtrack for this. The song 'Those Nights' in particular.


End file.
